In some implementations, there is provided an apparatus comprising a resonant amplifier circuit including a first inductor having a first inductive input and a first inductive output; a second inductor having a second inductive input and a second inductive output; a first switch coupled to the first inductive output; and a second switch coupled to the second inductive output, wherein the first switch and the second switched are driven out of phase, wherein the first inductor is configured to be resonant with a first capacitance associated with the first switch, and wherein the second inductor is configured to be resonant with a second capacitance associated with the second switch. Related systems and articles of manufacture are also provided.

An apparatus is disclosed for phase-shifting signals. In example implementations, the apparatus includes a phase shifter. The phase shifter includes a first port, a second port, a vector modulator coupled to the first port, and a signal phase generator. The signal phase generator includes multiple amplifiers coupled between the vector modulator and the second port. The signal phase generator also includes multiple capacitors that couple the multiple amplifiers together to form a loop. Each respective capacitor of the multiple capacitors is coupled between a respective pair of consecutive amplifiers of the multiple amplifiers to form the loop.

Transconductor circuits with programmable tradeoff between bandwidth and flicker noise are disclosed. An example circuit includes an input port, an output port, a plurality of transistors, and a switch arrangement that includes a plurality of switches, configured to change coupling between the input port, the output port, and the transistors to place the transconductor circuit in a first or a second mode of operation. An input capacitance of the transconductor circuit operating in the first mode is larger than when the transconductor circuit is operating in the second mode. In the first mode, having a larger input capacitance results in a decreased flicker noise because the amount of flicker noise is inversely proportional to the input capacitance. In the second mode, having a smaller input capacitance leads to an increased flicker noise but that is acceptable for wide-bandwidth applications because wide-bandwidth signals may be less sensitive to flicker noise.

Reconfigurable output baluns for wideband push-pull amplifiers are disclosed. In certain embodiments, a mobile device includes a transceiver that generates a first radio frequency signal of a first frequency band and a second radio frequency signal of a second frequency band, and a front-end system including a push-pull power amplifier that selectively amplifies one of the first radio frequency signal or the second radio frequency signal based on a band control signal. The push-pull power amplifier includes an input balun, an output balun, and a pair of amplifiers coupled between the input balun and the output balun. The band control signal is operable to control an impedance of the output balun.

Power amplifier systems including power amplifier modules (PAMs) and electromagnetic bandgap (EBG) isolation structures are disclosed. In embodiments, the power amplifier system includes a printed circuit board (PCB) and a PAM mounted to the PCB in an inverted orientation. The PCB has a PCB frontside on which a PAM mount region is provided, and radio frequency (RF) input and output bondpads. The PAM includes a topside input/output interface having RF input and output terminals electrically coupled to the RF input and output pads, respectively. The power amplifier system further includes a first EBG isolation structure containing a first grounded EBG cell array, at least a portion of which is located within or beneath the PAM mount region.

Power amplifier systems including power amplifier modules (PAMs) and electromagnetic bandgap (EBG) isolation structures are disclosed. In embodiments, the power amplifier system includes a printed circuit board (PCB) and a PAM mounted to the PCB in an inverted orientation. The PCB has a PCB frontside on which a PAM mount region is provided, and radio frequency (RF) input and output bondpads. The PAM includes a topside input/output interface having RF input and output terminals electrically coupled to the RF input and output pads, respectively. The power amplifier system further includes a first EBG isolation structure containing a first grounded EBG cell array, at least a portion of which is located within or beneath the PAM mount region.

Apparatus and methods for a low-load-modulation power amplifier are described. Low-load-modulation power amplifiers can include multiple amplifiers connected in parallel to amplify a signal that has been divided into parallel circuit branches. One of the amplifiers can operate as a main amplifier in a first amplification class and the remaining amplifiers can operate as peaking amplifiers in a second amplification class. The main amplifier can see low modulation of its load between the power amplifier's fully-on and fully backed-off states. Improvements in bandwidth and drain efficiency over conventional Doherty amplifiers are obtained.

Embodiments of RF amplifiers and packaged RF amplifier devices each include an amplification path with a transistor die, and an output-side impedance matching circuit having a T-match circuit topology. The output-side impedance matching circuit includes a first inductive element (e.g., first wirebonds) connected between the transistor output terminal and a quasi RF cold point node, a second inductive element (e.g., second wirebonds) connected between the quasi RF cold point node and an output of the amplification path, and a first capacitance connected between the quasi RF cold point node and a ground reference node. The RF amplifiers and devices also include a baseband termination circuit connected to the quasi RF cold point node, which includes an envelope resistor, an envelope inductor, and an envelope capacitor coupled in series between the quasi RF cold point node and the ground reference node.

A power amplifier module includes a first substrate and a second substrate, at least part of the second substrate being disposed in a region overlapping the first substrate. The second substrate includes a first amplifier circuit and a second amplifier circuit. The first substrate includes a first transformer including a primary winding having a first end and a second end and a secondary winding having a first end and a second end; a second transformer including a primary winding having a first end and a second end and a secondary winding having a first end and a second end; and multiple first conductors disposed in a row between the first transformer and the second transformer, each of the multiple first conductors extending from the wiring layer on a first main surface to the wiring layer on a second main surface of the substrate.

A multi-band power amplifier module includes at least one transmission input terminal, at least one power amplifier circuit that receives a first transmission signal and a second transmission signal through the at least one transmission input terminal, a first filter circuit that allows the first transmission signal to pass therethrough, a second filter circuit that allows the second transmission signal to pass therethrough, at least one transmission output terminal through which the first and second transmission signals output from the first and second filter circuits are output, a transmission output switch that outputs each of the first and second transmission signals output from the at least one power amplifier circuit to the first filter circuit or the second filter circuit, and a first tuning circuit that adjusts impedance matching between the at least one power amplifier circuit and the at least one transmission output terminal.